NAD has refreshed its top-of-the-line Master Series. Due out the end of the second quarter is the NAD Master Series M12 ($3499), a 2-channel audio hub that contains both preamp and DAC. Below it in the photo sits the M22 ($2499), a 2-channel class-D, dual-mono hybrid digital amplifier with an analog input stage and Encore Hypex digital module output stage. In a system that included Dynaudio's excellent C4 Signature and AudioQuest Rock series cabling, Esperanza Spalding's voice on her recording of "Little Fly" was flattered by the system's warm sweet sound. I wouldn't be surprised if Stephen Mejias, who speaks often of NAD's reliability and good sound, has his eyes on these babies.